Punooearm



P. M. McKAY.

ARTIFICIAL LIMB.

APPucATIoN FILED ocT. 31. 1911.

Patented Oct. 28,1919. 2 SHEETS-SHEET I IIIII I k WIIIIHHHMMLM.

lulI I II.

'P.M. McKAY.

ARTIFICIAL LIMB.

APPLlcATloN min ocr. 31. lsu.

1,319,884. Patented 001;. 28,1919.

2 SHEETS-SHEET 2.

. '1a V r. E 9

PETER MURRAY IVICKAY, OF NELSON, NEW ZEALAND.

ARTIFICIAL LIMB.

wire, and a pivoted thumb of hard material is normally held in theclosed or gripping position by a spring, and is opened by a cord orother flexible member connected to a part of the wearers body. Thefingers of such a hand are bent or straightened by the other hand of thewearer as occasion requires, and one object of this invention is toprovide a construction which will enable the central wires of thefingers to be readily replaced when worn out. To that end, the

`fingers are hollow and the stilfening wire can be inserted therein andwithdrawn through an opening provided in the hand. The openings for thestiffening wires are preferably located in the end of thewrist, andtheend of each wire can be connected by a screw to a metal plate, which isembedded in the hand.

At the wrist, the hand can be provided with a cylindrical plug adaptedto be inserted in a socket member attached to the wearers arm, and aspring catch is provided at the wrist of the hand adapted to engage anyone of a series of holes located in the socket member and concentricwith the socket. Thus the angular position of the hand relatively to thesocket member can be adjusted, and held in the desired position by thespring catch engaging one of the holes.

A thumb is provided to the hand, and is normally held in the closed orgripping position by a tension spring connected at one end to the palmof the hand and at the other end connected between the end of the thumband its pivot. The tension spring can be connected to the stiifeningwire in the index finger, and thus it can readily be removed andreplaced by a longer or shorter spring if desired. A flexible membersuch as a cord is connected to the basal end of the thumb and passesover a pulley situated on the Speccaton of Letters Patent.

Patented Oct. 28, 1919.

Application led October 31, 1917. Serial N' o. 199,400.

the tension of the spring. The cord passes up outside the wearers arm,across his back, and thence across his chest, and is finally connectedto a shoulder pad; guide pulleys being provided at the elbow andshoulder. By a suitable movement of the muscles of the chest andShoulder the cord can becaused to exercise a pull on the thumb and openit to the desired extent.

In the accompanying drawing,

Figure l is an elevation of the back of an artificial hand according tothis invention,

Fig. 2 is a side elevation partly in section,

Fig. 3 is a section on the line 3-3 in Fig. l, and

Fig. 4 shows the hand and the thumb operating flexible member inposition on the wearer.

The ngers A of rubber and fabric have a central hole B in which a wire Cof non-V resilient metal such as soft copper is inserted from the end ofthe wrist. The wire is formed with an eye D at one end through which ascrew E can be inserted and screwed into an angle plate F set in awooden block G which forms the base and wrist portion of the hand. Aplate H is fixed on the end of the wrist by a small screw I and acylindrical plug J both of which screw into the angle plate F. The plugJ is a good fit in a hole in a socket member K which is connected to thestump of the arm of the wearer, and when the plug is pushed home anannular groove J1 on the plug engages with a spring catch K1 on thesocket member K. This spring catch K1 can be of the kind described inBritish patent specification No. 13067 of 1916 'but any known type ofcatch can be used which is adapted to engage with the groove J1 and holdthe hand firmly in the socket and which can b e moved to release thehand when desired. The hand can be rotated in the socket member K, itsangular position being fixed by a spring catch I., the pin M of which isadapted to enter any one of the holes N formed on the outside of thesocket member in a series concentric with the hole which receives theplug J. The spring catch L is mounted on the plate H, and pressure onthe finger piece O compresses the spring P and thus lifts the pin M outof the holes N.

In the thumb Q a metal plate R is embedded and provided with two ears Swhich are pivotally connected to two ears extending from a plate Tembedded in the palm of the hand. A tension spring Ui is connected atone end to the plate R Vand at the other end is connected to thestiifening wire in the index finger. A cord V is connected at one end tothe base of the thumb and passes between the pulleys W, the other end ofthe cord being provided with an eye X. After the hand is connected ytothe socket, the eye X is connected to a strap Y (Fig. 4) which in turnis connected to a cord Y1 passing successively over pulleys Z and Z1 andthen joining to a strap Y2 which after passing across the back and thechest of the wearer is connected to the shoulder pad Ys. A strap Y4 isconnected to the strap Y2 where it passes under the armpit, and the saidstrap Y1 is connected to a waist-band or the like so as to relieve theupward pressure of the strap Y2 under the armpit. It will be obviousthat a suitable movement of the muscles of the chest and shoulder willmove the cord over its pulleys and cause the thumb to open against thetension of its spring.

Vhat I claim as my invention and desire to secure by Letters Patent isl. An artificial hand comprising hollow fingers composed of rubber andfabric; and renewable stifiening wires separately insertible into andwithdrawable from the hollow in each finger without impairing the hand,for the purpose described.

2. An artificial hand comprising hollow fingers composed of rubber andfabric; re-

newable stiifenng wires separately insertible into and withdrawablefromthe hollow in each finger without impairing the hand;

a metal plate embedded in the hand; and

means to connect the end of each wire to said plate after said wires areinserted, said means being accessible from the outside of the hand; forthe purpose described.

3. In an artificial hand, the combination of hollow fingerscomposed ofrubber and fabric; renewable stiifening wires separately insertible intoand Vwithdrawable from the hollow' in each finger without impairing thehand; a thumb pivoted intermediate its ends to the hand; a tensionspring connected at one end to the palm of the hand and at its other endto the thumb onone side ofits pivot; and a flexible member/operativelyconnected to the thumb on'the other side of the pivot.

4l. In an artificial hand, the combination of hollow lingers composed of,rubber and fabric; renewable stiflening wires separately insertibleinto and withdrawable," from the hello-w in each finger withoutimpairing the hand; a thumb pivoted intermediate its ends to the hand; atension spring connected at one end td one of the finger wires and atits other end to the thumb on one side of its pivot; and a flexiblemember operatively connected to the thumb on the other side of-A thepivot. In testimony whereof I aiiix mysignature.

PETER MURRAY MCKAY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

` Washington, D. C.

